Improvement in traction mechanisms for propelling machinery



G 2Sl1eets-Sheet 1. Traction Mechanism for Propelling Machinery.

No. 218,111. Patented Aug. 5, 1879.

Imanffiar NPETER84 PHOTO UTHOGflAPHER, WASHINGTON. D G.

2Sneets--Sheet 2. G. E. BURT.

Traction Mechanism for Propelling Machinery.

No. 218,111. Patented Aug. 5,1879.

byiiies'zy; jrzz/erziorr DLPETERS, PNOTO-UTHOGRAPHB. WASHINGTON. D C

UNITED- STATES PATENT QFFIOE.

GEORGE E. BURT, OF HARVARD, MASSACHUSETTS.

IMPROVEMENT lN TRACTION MECHANISMS FOR PROPELLING MACHINERY.

Specification forming part of Letters Patent No. 218,1 1 1, dated August 5, 1879-; application filed February 20, 1879.

To all whom it may concern.-

Be it known that I, GrEORGE EDWARD BURT, of Harvard, in the county of Worcester and State of Massachusetts, have invented a new and useful method and mechanism for transmitting power and increasing speed in a very small compass to propel machines-to wit, horsepowers, lawn-mowers, tedders, reapers, &c.--of which the following is a specification.

The nature of this invention consists in employing the contracting force of the internal arc of a circle to act on a train of tractionrolls, and thus holding them in contact with the surfaces of each other and the internal surface of the ring or circle, thus creating traction or propelling power sufficient to drive or propel various machines without the employment of cogs, as are now used in such machines.

I am aware that friction rolls or pulleys have been employed for transmitting motion for some purposes; but the devicesheretofore used to force the friction-rolls together caused a large amount of friction on the journals or bearings on which the friction-wheels turn; but by my method of employing the contracting arc of a circle and a series of traction-rolls, the force thus applied acts directly on the periph cry of the traction-rolls and the internal surface of the are, and relieves the journals or bearings of all the strain of the traction-force, and the power is doubled, as it acts upon two points of the opposite side of the traction-rolls and arc. The traction of the rolls may be diminished or increased by placing them so that their bearing on the arc shall be on the center of the extreme diameter of the ring, above or below it. As the traction-rolls recede from the center of the ring the traction-force of the arc is diminished. This force may be graduated to be more or less, as is desirable.

In the accompanying drawings, Figure 1 is a side view, showing the position of the propellin g-rin g, the incased traction-rolls, and the pulley or wheels to be propelled. Fig. 2 is a side view with the boxes and one-half of the frame and the casing of the traction-rolls removed, showing the position of the traction-rolls with each other and the propelling-ring and contractin g arer" Fig. 3 is a transverse longitudinaLsectional View through the traction-rolls,

showing the arrangement and construction of the various parts and their relation to each other. Fig. 4 is a side view of the ring, showing the traction-rolls placed on the are a considerable distance below the center of the diameter of the ring. F F are flanges. G is the groove.

These machines may be constructed of wrought or cast iron, steel, or hard gun-metal; for cheapness I use cast-iron. The ring and traction-rolls may be cast in chills, leavingtheir rolling-surfaces very hard, requiring but little finish, and being very durable. I make the ring A of the size, weight, and strength necessary for the work for which it is to be used. If I want a large amount of propellin g-force, I make the traction-rolls B B B of such diameterthat the united diameters of the three shall be equal to the internal diameter of the ring or are. This brings their surface-bearing on the center, or very nearly; if exactly on the center, the inward contracting force of the arc would be very great; but for practical use I make the traction-rolls to rest a little below the extreme diameter of the ring or are.

ln order to regulate the contracting force of the ring or arc, I make perpendicular slots I and sliding boxes E in the case or frame 0, for the journals or pivots, and regulate the position of the roll B by means of screws J J. (Shown in Fig. 1.) By placing the tractionroll B out of the line of the centers of the traction-rolls B B the space occupied by the three rolls is less than the diameter of the ring shown in Fig. 2, and by altering the position of the roll B the traction may be regulated. Thus the wear of the rolls and ring can be compensated for.

I construct the box E for the shaft D to hold the shaft in positive position; but the box E for the shaft 1) in the frame 0 permits the shaft to slide laterally. By this device the rolls come in contact, and rest against each other. (Shown in Fig. 2.) I attach wheels L to either of the shafts D of the rolls. If 1 wish to run a light machine, like a lawn-mower, I construct the traction-rolls of such a diameter in relation to the ring or are that the rolls will rest on a point considerably below the line of the center of the ring, substantially as shown in Fig. 4.

I construct the main frame 0 with projecting flanges K, curved to cover the traction-rolls Operation: When the propelling-ring A and and exclude dirt or any substance that might traction-rolls B B B are arranged substanwear or otherwise injure the rolls or propeltially as described, and motive power is apling-ring. It also prevents all liability to acplied to the ring A, and power or motion is to eident, which often occurs in the use of open be taken from the shaft D, the ring A should cog-wheels; and, when desirable, this boxing be made to revolve toward the shaft from may be extended around the internal are, makwhich the power is taken, as the traction-force ing a very strong frame for the propellingis greater when applied in the direction the ring and rolls to be operated in. I construct shaft and wheels revolve. the ring A with a groove, G, and rolls B B Having thus described the nature, construcwith flanges F F and grooves for the flanges tion, and operation of my invention, what I to run in. The flanges and grooves hold the claim as new, and desire to secure by Letters ring and rolls in line and in proper position Patent, is when in operation. (Shown in Fig. 3.) l. The method of transmitting motive power The rolls B B being of different diameter by aring and its contracting arcs, and a series gives more or less speed to the center-shaft of traction-rolls resting in contact with each Wheel D, which revolves two and a half times other and the arcs of the ring below the cento the end shaft 1) three times, and the wheels ter, provided with recesses and flanges, arturn in opposite directions. This method of ranged and covered within the periphery of transmitting motive power operates with less 1 the ring, for the purpose set forth. noise than the best out cogs, and is cheaper, I 2. The regulating-screwsJJand the oblong and is very desirable for some purposes. i box-seats E, in combination with traction-rolls In a 'iplying this invention to horse-powers, B 13 B and the ring A, operating substanthe ring may be used for the end spider or tially for the purposes set forth. drums; or the ring may be constructed with 3. The protecting-easing K KK, in combicogs to coginto the platfornrchain. The necnation with the traction -rolls B B B, the essary amount of traction on the rolls may be ring A, and frame (1, substantially as deregulated according to the amount of weight scribed. resting on the ring. The wheels L I. may be GEORGE EDWARD'BURT. changed from shaft to shaft, and the rolls may Witnesses:

be varied in their diameter, giving more or JAMES MONROE BARRY, less speed to the different shafts. l EDWARD JAMES MCLAUGHLIN. 

